Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.0 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SPF_PASS,T_MIXED_ES autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3F779C65BAE for ; Thu, 13 Dec 2018 23:13:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D8C2720851 for ; Thu, 13 Dec 2018 23:13:39 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=nestlabs.com header.i=@nestlabs.com header.b="Pe+unJua" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org D8C2720851 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=nestlabs.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-bluetooth-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726813AbeLMXNj (ORCPT ); Thu, 13 Dec 2018 18:13:39 -0500 Received: from mail-it1-f193.google.com ([209.85.166.193]:37262 "EHLO mail-it1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726236AbeLMXNj (ORCPT ); Thu, 13 Dec 2018 18:13:39 -0500 Received: by mail-it1-f193.google.com with SMTP id b5so6614140iti.2 for ; Thu, 13 Dec 2018 15:13:38 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nestlabs.com; s=google; h=mime-version:references:in-reply-to:reply-to:from:date:message-id :subject:to:cc:content-transfer-encoding; bh=MSCAsnhrA6JtQOilm5SULhh9LF4MdKjYnVO9EpUYO7Y=; b=Pe+unJuaNDhBvGldCnZLRh9Ev7Fl7M9b0dI0ytyZF2C8Q/zIxKfiIXrj3B7Sj8i8v5 tq1t+LyaD/t0IUcE4oczXLe+rDheA3QPPkBkSVQyCdoJIexKt+yq2cJQqZxPhivKeJrR YUO7t3UiBJooDzY30RvlZs/hpmLJV/mwk8jUw= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:reply-to :from:date:message-id:subject:to:cc:content-transfer-encoding; bh=MSCAsnhrA6JtQOilm5SULhh9LF4MdKjYnVO9EpUYO7Y=; b=ujbalXJzlGSOs/MYP+PMlVeTiqoCHv/UFTWlTsWQ8nFbDCMVxhWyHFx1qRgSA7p2Ae TDnLrZxOrSXtMf+R3zzMX2iXbBecTL5u/rnA36gEbDKA4FelrCsQUDrGtjwGSpXNWWlM xVr06BpS0yhfxK8RlEbbpuY4YPeD3OJvxWsCyJhmXKUe46AgSSHnWGBceD2kPTvkptHm gS+/4pDNBkTU+CYlxYSsGFcXxEbw+sgbIC9CjwQaWGBt//t67vcLRKn+h/MqCyhxk8ZP WGyq6TP7hxib/GzCIT89XhrG5HHGu3kJg+kpJ+/ovopHcwjpOhqxsRjpDCMhHeXv43rQ WI1Q== X-Gm-Message-State: AA+aEWbNn6UbP9b6omVB4pn8lj1WZO+THaNO8ZWYYSbu8EdnqYZXJlY1 /pPvN39mqMOwSiKQhQxxh05l3jUzVLMo5nOW5v4nBA== X-Google-Smtp-Source: AFSGD/VYXLn5tbqQyt5BZgvlI4a+UEgZm6/XyJC0CY59pZxAkQ88mvnIIqG5C3KyRtSg5hsq6vSns3WFG+LwZH24qoc= X-Received: by 2002:a24:b8c6:: with SMTP id m189mr1202898ite.72.1544742817825; Thu, 13 Dec 2018 15:13:37 -0800 (PST) MIME-Version: 1.0 References: In-Reply-To: Reply-To: yunhanw@nestlabs.com From: Yunhan Wang Date: Thu, 13 Dec 2018 15:13:26 -0800 Message-ID: Subject: Re: BLE advertisement re-enabling after ble connection goes away To: Martin Turon , Luiz Augusto von Dentz , Marcel Holtmann Cc: linux-bluetooth@vger.kernel.org Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Sender: linux-bluetooth-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-bluetooth@vger.kernel.org Hi, Luiz Rephrasing a little bit.. From what you describes, it seems Bluez is taking the responsibility to reenable the advertisement in peripheral side after the previous ble connection goes away. When I did local test, the ble peripheral is using bluez, I create gatt server and ble advertisment using Bluez DBus API, when remote connection in central disconnects, I see kernel in Bluez in peripheral side do receive HCI_EV_DISCONN_COMPLETE event, and trigger hci_req_reenable_advertising. Maybe you can share the code location where Bluez is reenabling the advertisement after ble connection goes away? Thanks Best wishes On Thu, Dec 13, 2018 at 3:10 PM Yunhan Wang wrote: > > Hi, Luiz > > From what you describes, it seems Bluez is taking the responsibility > to reenable the advertisement after the previous ble connection goes > away. > > When I did local test, the ble peripheral is using bluez, I create > gatt server and ble advertisment using Bluez DBus API, when remote > connection in central disconnects, I see kernel in Bluez do receive > HCI_EV_DISCONN_COMPLETE event, and trigger > hci_req_reenable_advertising. > > Maybe you can share the code location where Bluez is reenabling the > advertisement after ble connection goes away? > > Thanks > Best wishes > Yunhan > > On Thu, Dec 13, 2018 at 2:30 PM Martin Turon wrote: > > > > Hi Luiz, > > > > Is this behavior also expected on raw hci sockets? Because my observat= ion is that when working with raw hci over such sockets, auto-reenable does= not occur. > > > > #define BTPROTO_HCI 1 > > #define HCI_CHANNEL_USER 1 > > > > struct sockaddr_hci shci; > > shci.hci_family =3D AF_BLUETOOTH; > > shci.hci_dev =3D s_ble_hci_device; > > shci.hci_channel =3D HCI_CHANNEL_USER; > > > > s =3D socket(PF_BLUETOOTH, SOCK_RAW, BTPROTO_HCI); > > rc =3D bind(s, (struct sockaddr *)&shci, sizeof(shci)); > > > > Also, which API allows the user to control the advertising instances yo= u describe? Are they automatically created by the kernel when HCI is sent = to a raw socket to enable advertising? > > > > Thanks, > > Martin > > > > _____________________________ > > Martin Turon | Google > > > > > > > > On Thu, Dec 13, 2018 at 1:49 PM Luiz Augusto von Dentz wrote: > >> > >> Hi Yunhan, > >> > >> The BlueZ API operates a bit different than HCI, it keeps re-enabling = the advertisement if there is any instance active, but the user can stop th= is by removing its instance once a connection is made, this is considered m= ore convenient than having the user to reprogram the advertisement on every= disconnection. > >> > >> On Thu, 13 Dec 2018, 18:38 Yunhan Wang >>> > >>> +Martin > >>> > >>> Hi, Luiz and Marcel > >>> > >>> When I take a look at the bluetooth code, it seems it is re-enabling > >>> ble advertisement after ble connection goes away. Any idea? > >>> > >>> https://git.kernel.org/pub/scm/linux/kernel/git/bluetooth/bluetooth.g= it/tree/net/bluetooth/hci_event.c#n2634 > >>> https://git.kernel.org/pub/scm/linux/kernel/git/bluetooth/bluetooth.g= it/tree/net/bluetooth/hci_event.c#n2712 > >>> https://git.kernel.org/pub/scm/linux/kernel/git/bluetooth/bluetooth.g= it/tree/net/bluetooth/hci_request.c#n1386 > >>> https://git.kernel.org/pub/scm/linux/kernel/git/bluetooth/bluetooth.g= it/tree/net/bluetooth/hci_request.c#n1734 > >>> > >>> Thanks > >>> Best wishes > >>> Yunhan > >>> On Wed, Dec 5, 2018 at 6:54 PM Yunhan Wang wro= te: > >>> > > >>> > Hi, Luiz and Marcel > >>> > > >>> > May I have a question on ble behavior on BLE re-advertisement? > >>> > > >>> > According to Bluetooth spec Vol. 3 (the host volume), 9.2.4.2, "The > >>> > device shall remain in general discoverable mode until a connection= is > >>> > established or the Host terminates the mode." > >>> > > >>> > There is no description on re-enabling the advertising "after" > >>> > disconnection, so the responsibility for re-enabling the advertisin= g > >>> > is bluez or kernel or application code? In other words, does kernel= or > >>> > bluez or application would re-enable the ble advertisement after bl= e > >>> > disconnection happens? > >>> > > >>> > Thanks > >>> > Best wishes > >>> > Yunhan.